<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    body {
      margin: 0;
      padding: 15px;
    }
    .box-one {
      height: 100px;
      border: 1px solid #000;
      margin: 20px auto;
    }
    .box-two {
      height: 100px;
      border: 0.5px solid #000;
      margin: 20px auto;
    }
  </style>
</head>
<body>
  <div class="box-one"></div>
  <div class="box-two"></div>
</body>
</html>